Avalanche Forecast

Issued: Apr 8th, 2018 4:08PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Loose Wet and Wind Slabs.

jmcbride, Avalanche Canada

Northwest Coastal.

Rising freezing levels and light rain are the main concerns for the next few days. Watch for moist or wet snow especially at treeline and below. Recent wind slabs may also become more sensitive to triggering with the warming trend.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TONIGHT: Cloudy, wet flurries. Precipitation 3-6 mm. Ridge wind moderate, southwest. Alpine temperature near 0. Freezing level 1500 m.MONDAY: Cloudy, wet flurries. Precipitation 4-8 mm. Ridge wind moderate to strong, southwest. Alpine temperature near 0. Freezing level 1400 m.TUESDAY: Cloudy, wet flurries. Precipitation 5-8 mm. Ridge wind strong to extreme, southeast. Alpine temperature near 0. Freezing level 1600 m.WEDNESDAY: Mostly cloudy, flurries. Accumulation 4-8 cm. Ridge wind strong, southeast. Alpine temperature near 0. Freezing level 1400 m.

Avalanche Summary

On Friday and Saturday the Shames area saw a widespread natural cycle up to size 3 on solar aspects as a result of Friday's storm. See recent MIN report. While further north only isolated wind slab and loose, wet activity was reported. Read MIN report.On Thursday northern parts of the region saw a widespread natural avalanche cycle triggered by strong to extreme wind loading event in the alpine. There was also a report of an icefall triggered size 2.5 slab avalanche that failed on the mid-March interface, northwest of Meziadin Lake.Wednesday a natural avalanche cycle up to size 1.5 was reported on wind affected features, as well as skier triggered storm snow releases up to size 1. A natural cornice failure that released a size 1.5 slab was also reported from an east aspect in the Shames area. Read MIN report here.

Snowpack Summary

Strong to extreme winds have created widespread wind affect in the alpine and at treeline. Warming followed by cooling has created a surface crust exists on all aspects up to 1500 m which will likely break down with daytime warming, becoming moist or wet by the afternoon.In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

Problems

Loose Wet

Recent storm snow may become unstable with rising freezing levels and rain or wet snow.

Use caution above cliffs and terrain traps where small avalanches may have severe consequences.Use extra caution on slopes if the snow is moist or wet.Be increasingly cautious on sun exposed slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Wind Slabs

Strong to extreme winds have formed widespread wind slabs in leeward areas in the alpine. With warming temperatures these slabs may be sensitive to light triggers, such as a small slough or skier/rider.

Pay attention to overhead hazards like cornices which may become fragile with daytime warming.Be careful with wind loaded areas, especially near ridge crests and roll-overs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 9th, 2018 2:00PM